1. Field of the Invention
The present invention relates to a synthesis of an 8-membered carbocyclic compound having diexomethylene groups, more particularly to a synthesis of an 8-membered carbocyclic compound having diexomethylene groups, a novel compound having the structure represented by the following Chemical Formula 1, from trimethylsilanylmethyl-allenol derivative by the intramolecular Prins cyclization using Lewis acid. The 8-membered carbocyclic compound is a useful intermediate for synthesis of other multicarbocyclic compounds. 
In Chemical Formula 1, R1 is a phenyl group, and R2 and R3 is respectively a hydrogen atom, or R1, R2 and R3 may be connected with neighboring substituents to form a 5 to 10-membered aliphatic or aromatic ring.
2. Description of the Related Art
8-membered carbocyclic compounds are important ingredients of biologically active natural substances and medicines. Recently, they are gaining interest in genetics because they are known to take part in cell division. For example, Taxol, which is widely known as anticancer drug [Taxane Anticancer Agents, ACS Symposium Series 583], has an 8-membered ring. Besides, since 8-membered carbocyclic compounds have good biological activities, development of an 8-membered carbocyclic compound with a new structure is a prerequisite for drug researches.
A carbocyclic compound having diexomethylene groups can be expanded to other multicarbocyclic compounds through Diels-Alder reactions. Therefore, the compound represented by Chemical Formula 1, which has diexomethylene groups, is a very useful intermediate in synthesizing a multicarbocyclic compound via Diels-Alder reactions.